The present invention relates to the improvement in the resiliency of response of inflatable flexible-walled chambers, and liquid-fillable flexible walled chambers whenever, under normal conditions of use, external pressure is applied to the chambers. Examples of such inflatable/fillable devices include air mattresses, air cushions, and waterbed mattresses. The novel principle is also applicable to the improvement in the response-action of the familiar automobile safety airbag.
In my previous teaching (U.S. Pat. No. 5,608,931) I described the use of internal springlike couplings which were attached at coupling ends to the interior walls of the airchamber. Each springlike, or elastic, member was characterized by a predetermined length in its fully extended, unstretched condition, and was elongated by the outward relative movement of the flexible chamber walls upon the application of inflationary pneumatic pressure. The elastic member was further elongated when an external mechanical force was applied to the chamber during normal use, e.g., the placement of the user's body onto the surface of an airmattress; it was during this latter stage of elongation when the improvement in the overall resiliency, or comfort, of the mattress was produced. Embodiments were covered wherein a multiplicity of such elastic members were employed, both as groups, and singly in spaced relationship along the interior walls of the airchamber. In said embodiments, some elastic members or couplings were different in length from others, some members were of differing strengths (moduli) from others, and wherein some members were of both differing lengths and moduli. The overall result of such embodiments was a further improvement in resiliency and comfort according to the enunciated "variable response" principle.
In my co-pending U.S. patent application Ser. No. (08/794,945) now U.S. Pat. No. 5,852,839 I teach the attachment of springlike couplings to the exterior walls of inflatable air chambers. This concept affords improvement in the ease of manufacture of such devices as airmattresses, as well as ease in inspection and replacement of worn or broken couplings. Furthermore, portions of the flexible walls means of the sealable, inflatable airchamber can themselves be fabricated from elastic material.
In all the foregoing embodiments, the flexible-walled airchambers are deformed at and near to the points of attachment of said couplings to said walls, when the device is in its inflated "rest" condition, e.g., before a person lies down upon the mattress. This deformation gives rise to the familiar "tufting" of the action-surface of the mattress whenever internal couplings are attached at their ends to the interior top and bottom walls of the chamber in spaced position along said walls. Then, upon application of said exterior mechanical force, this tufting tends towards a non-tufting "regular" surface both at points of application of said exterior force (beneath the person's body) and at all other points along the surface of the airchamber.
When elastic couplings are attached at their ends to the exterior surface of the flexible-walled airchamber, however, "tufting" as it is normally understood does not exist when the chamber is in its "rest position", i.e., inflated to a predetermined chamber pressure. Instead, a crimping of flexible wall material occurs, for example, between the two end-points of an elastic coupling where they are attached to said wall. Upon application of exterior mechanical force to the airchamber, this crimping tends to smooth out. Such crimping, as it occurs across the chamber surface whenever a multiplicity of elastic members is employed, follows a pattern that is dictated by the placement of elastic couplings across said surface.
It is the principle object of the present invention to provide an improved means of application of elastic control of the action surfaces of inflatable airchambers.
One object is to replace attached elastic couplings with continuous elastic bands, or metal or plastic springs, in a girth-like manner encompassing the airchamber.
Another object is to extend the applicability of the improved resiliency afforded by elastic bands, or springs, to a wide variety of airchamber shapes, and thus to a much wider range of airchamber uses.
Yet another object is to improve the ease of manufacture, inspection, and replacement of resiliently-acting airchambers by employing elastic means which embrace said airchambers without actually being attached to the surfaces of said chambers.
Another object is to employ girth-like elastic couplings to any and all exterior airchamber surfaces, so as to optimize the end-use viability of the device, including the so-called "action surfaces", e.g., the top of a seat cushion.
A further object of the present invention is to provide resiliency to the action of liquid-filled flexible-walled devices such as water mattress components.
Yet another object of the invention is to create an improved automobile safety airbag action response which will be gentler upon the auto passenger, through the design of the airbag which provides for elastic girth-like means to resiliently restrain the expansion of the airbag upon activation.
A further object of the invention is to create a novel type airbed which is simpler in design and manufacture than those heretofore available.
Perry (U.S. Pat. No. 2,360,715) has disclosed an inflatable rectangular-shaped seat cushion, " . . . the sides of which are constructed so as to be deformable and have cooperating therewith elastic means tending to urge the deformed portions to their normal positions.", i.e., once the user sits on the cushion. He also describes " . . . resilient means embracing and cooperating with all said side members [side walls of the seat cushion] for normally deforming said side members inwardly . . . ". Although he teaches application to a cushion " . . . in which a main, weight-bearing, air-inflated body is made of semi-elastic or non-elastic material . . . ", he does not specifically designate that the "resilient means embracing" must be more resilient than the "semi-elastic material" of the body of the device in order for the invention to be operable. Indeed, I teach that if the elastic modulus of the "resilient means embracing" is equal to or greater than that of the body of the cushion, at the point of application, then the device is not operable. Furthermore, he teaches " . . . it must be understood that the upper and lower surfaces of the cushion are provided with some means for holding them in definite relationship to each other . . . " Here he is referring to interior structural elements which give rise to the "tufting" mentioned earlier in this section. As will be seen in the more detailed discussion of my invention, such interior structural elements may be incorporated into the embodiments of my invention, but are totally optional. Indeed, regarding the spherical and tubular chambers of my invention, such internal structural members are superfluous.
Other objects will in part be obvious and will in part appear hereinafter.